title: A century of Helicobacter pylori: paradigms lost-paradigms regained.
abstract: The investigation of gastric bacteria properly began in the latter half of the nineteenth century when microscope resolution had sufficiently advanced. Whilst a bacterial etiology was demonstrated for dysentery, tuberculosis and syphilitic ulcers, problems in the isolation and culture of pure strains circumvented a role for bacteria in gastric pathology. Furthermore, dogma and the intellectual chorus were in harmony advocating that gastric acid was critical in ulcer disease. The consideration of a role for a pathogen or pepsin was regarded as whimsical in the context of mucosal ulceration. Indeed, the effects of acid inhibitory agents were held as gospel truth whilst the use of antibiotics or metallic ions were deemed to be quackery or at least ill judged. Nonetheless, spiral-shaped bacteria had been identified in both mucosa and gastric contents of patients as early as 1889. Elegant studies had documented the infectivity of these organisms, and suggested but not proven a causative role in gastric disease. The prescient identification by Doenges of organisms associated with gastritis in both man and monkey, was buried by the observations of Palmer, and an opportunity for early progress lost. It required two decades and Antipodean pathological perspicacity to elucidate the warren of previous archaic gastric bacterial misinformation. The subsequent marshalling of clinical and pathological data established the fatal flaw in the mucosa to be bacteria and not only acid on the mucus shore. It is now widely apparent that Helicobacter is ubiquitous, pathological and, a century after its initial discovery, still remains a paradox of as yet incompletely determined biological consequence. It is of note that an organic helical configuration has twice in this century provided biological information of unique import.
authors.affiliation: Gastric Surgical Pathobiology Research Group, Yale University School of Medicine, New Haven, Conn. 06520-8062, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kidd
authors.forename: I M
authors.initials: IM
authors.lastname: Modlin
mesh_terms: D005767:Gastrointestinal Diseases / Q000266:history* / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000266:history*; D016480:Helicobacter pylori / Q000302:isolation & purification; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans